Shell dating

The remains of shellfish are found throughout the pacific and provide a wealth of information about economy, culture, environment and climate.

Research at the Waikato Radiocarbon Dating laboratory has highlighted differences in 14C value for many commonly dated Pacific shellfish species and has demonstrated the importance of tailoring sample selection to species habitat and dietary preferences, as well as local ocean conditions.


Weipa shell mounds project (Photo courtesy Tim Mackrell, Auckland University).


Related research projects:

  • Human-environment interaction in Australia's tropical north: The Weipa shell mounds

Selected publications:

  • Petchey F., Dabell K., Clark G., & Parton P. 2023. Evidence of temporal changes in the marine 14C reservoir in the South Pacific and implications for improved dating resolution across a radiocarbon plateau (2600-2350 cal BP). Journal of Archaeological Science,
  • Petchey, F., Piper P., Dabell K., Brock F., Turner H., Dzung LTM., 2022. Dating Thach Lac: Cryptic CaCO3 diagenesis in archaeological food shells and implications for 14C . Radiocarbon, 64(5):1093-1107.
  • Petchey, F. and Clark G., 2021. Clarifying the age of initial settlement horizon in the Mariana Islands and the impact of hard water. A response to Carson 2020. Radiocarbon, 63(3): 905-913.
  • Petchey, F., & Schmid, M., 2020. Vital evidence: Change in the marine 14C reservoir around New Zealand (Aotearoa). Implications for the timing of Polynesian settlement. Nature – Scientific Reports. Available:
  • Petchey, F.2020. New evidence for a mid- to late-Holocene change in the marine reservoir effect across the South Pacific Gyre. Radiocarbon, 62(1):127-139;
  • Petchey F., & Kirch, P.V., 2019. The importance of shell: Redating of the To’aga site (Ofu Island, Manu'a) and a revised chronology for the Lapita to Polynesian Plainware transition in Tonga and Sāmoa. PLOS One, 14(9):
  • Petchey F, S Ulm, B David, IJ McNiven, B Asmussen, H Tomkins, N Dolby, K Aplin, T Richards, C Rowe, M Leavesley and H Mandui, 2013. High-resolution radiocarbon dating of marine materials in archaeological contexts: Radiocarbon marine reservoir variability between Anadara, Gafrarium, Batissa, Polymesoda and Echinoidea at Caution Bay, Southern Coastal Papua New Guinea. Archaeological and Anthropological Sciences, 5(1):69-80.